Recently, as a recording medium to/from which digital data can be written/read, various media are developed including SD Memory Card (registered trademark), is Memory Stick (registered trademark), Compact Flash (registered trademark), and other semiconductor memories (or memory cards). A hard disk with small size and large capacity is also widely used.
The data processing apparatus for processing data using the semiconductor memory and the hard disk is applied in various electric products such as personal computer, audio appliance, video appliance, cellphone and digital camera.
A large capacity hard disk is useful as storage device for storing a large capacity of data in a product. A detachable and portable recording medium such as semiconductor memory is particularly useful as bridge medium for exchanging data between data processing apparatuses.
In the recording medium used as such bridge medium, data recorded by one data processing apparatus may be updated by other data processing apparatus. In this case, due to mishandling by the user, or the like, the data may be moved away to a position at which the data should be positioned essentially. For example, while viewing a content in a recording medium using browser software of a personal computer, the data may be moved to other directory, unknowingly by erroneous operation of a mouse or other input device.
Regarding the recording medium used as such bridge medium, copyright protection is should be taken into account. Concerning an apparatus which can play back copyright-protected music data stored in a portable recording medium, a recording method and playback method thereof are disclosed, for example, in patent document 1.
According to the disclosed method, using a personal computer or the like, a plurality of encrypted music data, meta information relating to the music data, and play list for defining play back sequence of the music data are stored in a portable recording medium. Further, the recording medium is loaded in the personal computer or a portable electronic appliance. The appliance searches a specified position for the data to play back the music data according to the play list stored in the loaded recording medium.
Patent document 1: JP-A-2001-249693